This invention relates to an article of manufacture for use as an implant in the animal ear to correct a faulty carriage of the ear occasioned by the presence of a skin-enclosed cartilage fault, and to an implantation method employing the article.
Implants have been employed in the past to support weak or defective auricular cartilage in the animal ear, especially in the canine ear. The implants are used in cropped ears that fail to stand and in ears having damaged cartilage. In one technique, a surgical incision of substantial length is made in the skin along the length or longitudinally of the canine ear, across an area of weak or defective cartilage. The edges of the skin around the incision are spread apart so as to expose the cartilage over which an implant is to be laid, an elongated implant is put in place, and the skin overlying the implant is closed by suturing, after which an antibacterial dressing is applied and the ear is placed in a supporting bandage. A preferred implant material is porous polyethylene. Cartilage and tissue growth is stimulated, and such growth together with the implant provide sufficient rigidity to maintain an erect posture of the ear, with sufficient flexibility to retain the natural feel of the ear. The method and implant are disclosed in U.S. Pat. No. 4,010,494.
In my copending application Ser. No. 768,101, filed Feb. 14, 1977, now U.S. Pat. No. 4,147,164, I have disclosed and claimed an improved implantation method, wherein an elongated implant is inserted through a small or short incision in the skin of the ear, extending transversely of the ear, and into a pocket previously formed between the skin and cartilage over a cartilage fault, so that the implant bridges the fault. The insertion of the implant into the pocket is accomplished by first inserting a cannula-like sheath through the incision and into the pocket so that the sheath bridges the fault, thereafter inserting the implant endwise into the sheath, and removing the sheath from the pocket and from around the implant to deposit the implant in the ear in bridging relationship to the fault. The improved method has the advantages over the method dislosed in the above-identified patent, of reducing the required number of surgical steps, simplifying the closing of the incision, being more amenable to the maintenance of sterility, remarkedly reducing the number of sutures and requiring no internal absorbable sutures, and being performed in a substantially shorter period of time.
The porous polyethylene implant preferably employed prior to the present invention had a tendency to move under the skin under normal conditions of use, and at times would work out through the incision, the sutures being spread apart in the process. Also, abscessing occurred in a sizeable number of canine ears, due to foreign body reaction, and the implants worked out from beneath the skin where abscessed. The working out of an implant results especially from the dog shaking his head.